Nickel-sheathed MgB2 tapes were fabricated by using the powder-in-tube method, with a monocore configuration for the superconductor. The metallic tubes were filled with commercial reacted powders and cold-worked by groove rolling, drawing or rolling to flat tapes of about 4mm in width and 0.35mm in thickness. Portions of the manufactured conductors were heat-treated in an Ar atmosphere at up to 940C. The conductors were characterized by transport measurements in order to determine the magnetic field dependence of the critical current density and the irreversibility line, as well as to establish an initial relationship between the thermomechanical treatment and the current-carrying capacity of the manufactured MgB2 samples. Optimized samples for low-field operation carried a critical current density of at least 4 x 105A/cm2 at 4.2K and 1T. The main conclusion was that the optimum heat treatment condition changed depending upon whether the MgB2 had to be used for low- or high-field operation. The first successful demonstration of the current-carrying capability of longer MgB2 tapes was reported here.

Fabrication and Properties of Monofilamentary MgB2 Superconducting Tapes. G.Grasso, A.Malagoli, M.Modica, A.Tumino, C.Ferdeghini, A.S.Siri, C.Vignola, L.Martini, V.Previtali, G.Volpini: Superconductor Science and Technology, 2003, 16, 271-5